The thing named Rosetta (actually Rosetta 2) for the x86_64 -> ARM transition is technologically completely unrelated to the PPC -> x86 Rosetta, and has none of the problems you mention. There's no user-observable difference between a program using Rosetta and a native program in modern macOS, and porting programs which didn't have any assembly or other CPU-arch-specific code was generally just a matter of wrangling your build system.

I addressed that in my response here: https://news.ycombinator.com/item?id=43720758